Carrier bag



Sept. 23, 1969 K. H. SENGEWALD 3,468,470

CARRIER BAG Filed Nov. 24, 1967 2 Sheets-Sheet 1 230 I4 23 F IG. 3

.INVEN r09. KARL HEINZ SENGEWALD Sept. 23, 1969 K. H. SENGEWALD CARRIER BAG 2 Sheets-Sheet I,

Filed Nov. 24, 1967 FIG. 4

FIG. 7

INVENTOR KARL HEINZ SENBEWALD United States Patent 3,468,470 CARRIER BAG Karl H. Sengewald, Dr. K. H. Sengewald, 4801 Kunsebeck, Westphalia, Germany Filed Nov. 24, 1967, Ser. No. 685,668 Claims priority, application Germany, Nov. 23, 1966, S 107,086; Sept. 30, 1967, S 112,234 Int. Cl. B65d 33/08, 33/10 US. Cl. 229-54 8 Claims ABSTRACT OF THE DISCLOSURE The invention relates to a carrier bag made of a foil of synthetic thermoplastic material, provided with lateral folds on both sides.

The object of the invention is to provide a carrier bag, whose entire external surface can be printed with relatively simple means, and which has a reinforcement extending over the whole of its height and also over a substantial portion of its width. To achieve this end, hitherto considered impossible, it is proposed according to the invention to constitute said carrier bag of a printed band of synthetic thermoplastic foil, which is provided with two reinforcing strips symmetrically spaced relative to the median longitudinal axis thereof, which, in the finished bag, extend over the whole of the height and are arranged in the width in the region comprised between the lateral folds provided on both sides of the carrier bag, these folds being produced after folding of the flat band about the median longitudinal axis and the longitudinally extending weld seam closing the hose thus formed. The carrier bag is further provided with a bottom weld seam and has on its upper open end apertures punched into the strip-reinforced wall portions.

According to a further feature of the invention, the longitudinal weld seam joins the two lateral folds along their line of folding. This feature facilitates the provision of the weld seam, since the latter is then obtained by welding together the edges of the half-hose resulting from the folding of the fiat foil band about its median longitudinal axis, which edges are pressed inwards following the completion of the longitudinally extending weld seam. Hitherto, it was not considered possible to produce lateral folds following a welding along the line of joint between the lateral folds. However, this can be achieved with the aid of a combination consisting of a carriage arranged in the interior of the hose and a blade or roller cooperating therewith from outside the hose, which pushes inwards the edge of the hose to form the lateral folds.

According to a further feature of the invention, the external Walls of the carrier bag are flat, and the gluedon reinforcing strips are provided on the inner faces turned towards each other.

Lastly, in a modified form of embodiment of the invention, the lateral folds on one edge of the hose have different depths, and the lateral fold of greater depth is joined on its outward-projecting edge with the edge of the associated hose wall by means of a longitudinal Weld seam.

3,468,470 Patented Sept. 23, 1969 According to another feature of the invention, the longitudinally extending weld seam is located within the fold on one side of the carrier bag. It is achieved hereby, that owing to its location said longitudinally extending weld seam is practically invisible.

According to yet another feature of the invention, the thickness of the reinforced wall of one side of the carrier bag corresponds to the unreinforced wall portion in the region of the lateral folds of the carrier bag edges augmented by the thickness of a lateral fold. However, the thickness of the reinforced wall on one side of the carrier bag may also be greater than the thickness of the nonreinforced wall portion in the region of the lateral folds on the edges of the carrier bag, augmented by the thickness of a lateral fold. According to a further feature of the invention, the gripping edge protrudes over the upper edge of the carrier bag, and the horizontally extending axis of symmetry of the oval grip aperture is arranged at the level of the upper edge of the carrier bag.

For producing the aforedescribed carrier bag, it is proposed according to the invention to affix to a foil, preferably by pasting, two reinforcing strips uniformly spaced relative to the median longitudinal axis of said foil, thereafter bending the foil by 180 about its median longitudinal axis to form a hose open at one edge and producing on the two longitudinal edges of said hose lateral folds in such a manner, that the lateral folds of one edge differ from each other in depth, joining thereafter the fold of greater depth on its outward-projecting edge to the edge of the adjoining hose wall by a longitudinal weld seam, or closing the half-hose along its open longitudinal edges by welding and then producing the lateral folds, followed by a transverse closure weld with a separating out to form the bottom of the carrier bag. It is further proposed to form the grip aperture and the contours of the upper edge of the carrier bag by stamping simultaneously with or after the transverse closure weld.

The invention will now be described with reference to the accompanying drawings, which illustrate the invention but in no restrictive sense.

FIGURE 1 shows a carrier bag according to the invention, in side elevation;

FIGURE 2 shows a flat foil with aflixed reinforcing strips for producing the carrier bag of FIGURE 1, in sectional and perspective view;

FIGURE 3 is a section through the carrier bag, taken along the line III-III of FIGURE 1;

FIGURE 4 illustrates another carrier bag according to the invention, in side elevation;

FIGURE 5 shows in perspective view the flat foil with affixed reinforcing strips for producing the carrier bag of FIGURE 4;

FIGURE 6 illustrates sectionally the closure of the foil band bent into a half-hose for producing the carrier bag of FIGURE 4; and

FIGURE 7 is a section through the carrier bag of FIGURE 4, taken along the line VII-VII.

The carrier bag 10 consists of a foil made of a synthetic thermoplastic material. It is produced from a fiat foil 11 illustrated in FIGURE 2, whose downward-turned surface, referenced 12 in FIGURE 2, is printed. This fiat foil 11 is very easy to print, in particular over its entire surface. After printing, two identical reinforcing strips 13 and 14 are affixed to the unprinted upper face of the fiat foil 11, symmetrically relative to the median longitudinally axis 15 of the foil. The affixing of the strips is carcaried out continuously with the aid of a pasting adhesive, which makes it possible to affix about metres of reinforcing strips 13, 14 per minute. The application of a pasting adhesive offers the advantage that in spite of the indicated high rate of production no twisting of the foil 11 occurs, and the latter remains completely smooth on the outside. The reinforcing strips 13 and 14 could also be joined to the foil by thermal effects, or layers of said foil could also be welded together. However, the use of a pasting adhesive, especially of a two-component adhesive, is more advantageous.

After the rein orcing strips 13, 14 have been affixed to the foil in the aforedescribed manner and location, the foil 11 is bent by 180 about the median longitudinal axis 15 in the direction indicated by the arrow. This brings the reinforcing strips 13 and 14 in positions precisely opposite each other, as can also be seen in FIGURE 3 showing the finished carrier bag.

Following this formation of a hose from the foil 11, which is open at the left-hand edge shown in the drawing, the lateral folds 17 and 18 are produced in the right-hand edge of the hose, and corresponding folds 1), 20 are produced on the left-hand edge of the hose. The folding line 21 between lateral folds 17 and 18 then corresponds to the median longitudinal axis 15 of the original foil 11.

FIGURE 3 shows, that the front bag wall 22 in the side elevation of FIGURE 1 has a smaller width than the rear bag wall 23. Moreover, the depth of lateral fold 20 is shallower than that of lateral fold 19. On the lefthand side therefore the lateral fold 19 overhangs the left frontal edge 24 of the carrier bag, which is also overhung by the rear wall 23. This arrangement is provided in order to make possible the continuous joining of the externally located edge 19:: of lateral fold 19 and the edge 23a of the rear wall 23 by means of a longitudinal weld seam 25, without being hindered by either the hose edge 24- or the lateral folds 19 and 20. The required welding bars, which may also be heated rollers, are referenced with 26 and 26a.

After completion of the longitudinal weld scam, the transverse weld 27 with the separating cut 28 is effected by sections to form the bottom of the carrier bag and to separate a carrier bag from the hose. The contour of the grip aperture 29 and the contour of the carrier grip 30 can also be simultaneously produced by stamping while effecting this transverse weld. It is obvious that instead of the oval grip aperture 29 here shown the grip aperture may also have a non-annular form.

In addition to the embodiment shown in FIGURE 1 with a carrier grip 3d projecting above the upper edge 31 of the carrier bag, said upper edge may also be formed so as to be completely horizontal, in consequence of which the grip aperture 29 will be located below the edge 31.

The reinforcements 13 and 14 within the carrier bag, located on portions of walls 22 and 23 facing each other, extend not only over the entire height of the carrier bag, but also over a substantial part of the width thereof. Their width is such, that they extend in close proximity of folding line 21 of the lateral folds 17 and 18 and of the folding line 32 of lateral folds 19 and 20. Moreover, the thickness of the reinforcements 13 and 14 preferably corresponds to the thickness of foil 11. It will be ensured hereby, that when the carrier bag is laid fiat with the reinforcements 13 and 14 touching each other, the overall thickness of the carrier bag will be the same over the entire width of the bag. In order to obtain a carrier bag of high dimensional stability and mechanical strength in spite of using a relatively thin foil material, the reinforcements 13 and 14 may consist of a relatively stronger or more rigid foil material. However, it is also possible to select the thickness of the reinforcements 13, 14 greater than that of the foil, in particular by taking into account the feature whereby the reinforcements 13, 14 are of a relatively great width, and thus when the carrier bag is laid fiat they bear against each other with a correspondingly large surface, so that carrier bags stacked one upon another do not slip off the stack.

There is thus provided according to the invention a carrier bag which, for a relatively small expenditure in material has a high carrier strength and which at the same time can be printed and is preferably printed on all its external surfaces, inclusive of the external surfaces of lateral folds 1'7, 18, 19 and 20.

According to FIGURE 4, the carrier bag 19 is likewise produced from a printed fiat band 11, on which reinforcing strips 13 and 14 made of paper or plastic have been afiixed symmetrically relative to the median longi tudinal axis of the flat band 11 and joined thereto by means of a pasting adhesive. Following this, the hat band is bent about the median longitudinal axis 15 to form a half-hose, as can be seen in FIGURE 6. The two reinforcing strips 13 and 14 are then located opposite to each other. The two oppositely located edges 33 and 34 of the half-hose of FIGURE 6 are then continuously welded together, preferably by ultrasonics. Lateral folds are then produced in the resulting hose, folds 17, 18 on one side and folds 19, 21 on the other. The lateral folds 19 and 20 are joined by the weld seam 25 shown in FIGURE 7. In the finished carrier bag, this weld seam will therefore be located within the fold, practically invisible from the outside. The hose is then provided with a bottom weld seam 27.

In the region of the upper filling end of the carrier bag, a grip aperture 29 in each case is punched into the reinforcing strips 13 and 14 and in the associated walls of the carrier bag.

For the sake of simplicity in the drawings, FIGURE 5 shows the reinforcing strips 13 and 14 as being at a small distance from the median longitudinal axis. The real proportions are apparent from FIGURES 6 and 7, according to which the reinforcing strips extend over a distance in width which approximately corresponds to the distance between the lateral folds located opposite to each other on the two sides of the carrier bag, and as a rule is somewhat smaller than this distance.

What I claim is:

1. A reinforced carrying bag adapted to be economically produced from a printed flat band of material having reinforcing strips afiixed thereto symmetrically spaced relative to the median longitudinal axis of the band, said bag comprising printed walls made of synthetic thermoplastic foil; one reinforcing strip adhered to each of two opposite side walls of said bag; the other two opposite side walls of said bag provided with inwardly bending lateral folds to make said bag collapsible and generally rectangular in opened cross-section; said strips adhered to and extending in length over the entire longitudinal length of said opposite side walls and in width, to a region adjacent said lateral folds in collapsed condition; a longitudinal weld seam connecting the two longitudinal edge portions of said printed flat band; a transverse bottom weld seam; and on its upper open end, a grip aperture in the strip-reinforced side wall portion of each of said two opposite side walls.

2. A carrier bag according to claim 1, wherein the longitudinally extending weld seam is located within the lateral fold on one of the said other two opposite side walls of said bag.

3. A carrier bag according to claim 1, wherein the longitudinally extending weld seam joins one of said two opposite side walls to one of said other two opposite side walls adjacent their longitudinal edges.

4. A carrier bag according to 1 wherein the external walls are smooth the adhered reinforcing strips being located on the inside of said bag, and furthermore said reinforcing strips are adhered by an adhesive.

5. A carrier bag according to claim 1 wherein the lateral folds differ in depth on one of the said other two opposite sides of the bag, and the lateral fold having greater depth is joined along its outward-projecting edge with the edge of one of said two opposite side walls by means of the longitudinal weld seam.

6. A carrier bag according to claim 1 wherein the thickness of the reinforcing strips corresponds to the thickness of the side walls so that when collapsed, the carrier References Cited bag will lie fiat.

7. A carrier bag according to claim 1 wherein the thick- UNITED PATENTS ness of the reinforcing strips are greater than the thick- 2,773,636 12/1956 Wllhams at a] 22955 ness of the ide walls 8. A carrier bag according to claim 1 wherein the rein- 5 3,285,497 11/1966 stlnman at 229 55 forced side wall portions containing the grip apertures 3,302,860 2/1967 Schwarzkopf ISO-12 project above the upper edge of the carrier bag, the aper- I tures being oval and the horizontally extending axis of DAVID BOCKENEK Pnmary Exammer symmetry of the oval grip apertures being arranged at the 10 US. Cl. X.R.

level of the upper edge of the carrier bag. 150-12; 229--55 

